I don't even know where to start on this.

• Fresh install != no bugs
• Several times on two platforms isn't more than a weak indicator. Simple configuration changes can account for much more than that, as can the client implementation. This is not really an OS test.
• Most folks have a connection < 1 mbps, which isn't going to peg any reasonable machine. Even T1 is only 1.5 mbps. If you want to test throughput do it on a LAN, preferably something like 1 gbps copper.

Certainly Linux has advantages, and the new release (coming soon to a ftp site near you!) will erode several places where Windows has clear advantages over Linux in the realm of socket connection processing, but this sort of thing is way more interesting to the folks who are doing web servers and such. Client side stuff is going to be more about 'perception of speed', not reality.